Device for mounting the toe and heel ends of a shoe upper

ABSTRACT

The toe and heel ends of the mounting last, in a shoe-making process, act as forming elements in the shaping of the upper in combination with a die comprising impressions of the shoe to be obtained. This die comprises on the one hand a frame element of semi-rigid but resilient material which includes a base carrying at least one curved rib corresponding substantially to the outer contour of the toe end of the shoe contemplated and on the other hand a filling element of flexible, soft and resilient material, fitted in the cavity formed by said curved rib.

United States Patent [191 Holt et al. [451 Jan; 2", 1974 [54] DEVICE FOR MOUNTING THE TOE AND 2,292,930 ll/l942 Daniels 12/543 HEEL ENDS ()F A SHOE UPPER $689953 Inventors: Terence Albert Holt; Jean-Gabriel Barre, both of Lyon, France Assignee: Centre Technique du Cuir, Lyon,

France Filed: Nov. 17, 1972 Appl. No.: 307,558

References Cited UNITED STATES PATENTS 10 1954 Altvaterlm. ..12/54.2 9 1931 Kinney ..12 s.1

Dawson ct nl. l2/l4.4

Primary ExaminerPatrick D. Lawson Attorney, Agent, or FirmKarl F. Ross et a1.

57 ABSTRACT The toe and heel ends of the mounting last, in a shoemaking process, act as forming elements in the shaping of the upper in combination with a die comprising impressions of the shoe to be obtained. This die comprises on the one hand a frame element of semi-rigid but resilient material which includes a base carrying at least one curved rib corresponding substantially to the outer contour of the toe endof the shoe contemplated and on the other hand a filling element of flexible, soft and resilient material, fitted in the cavity formed by said curved rib. v v

5 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION DESCRIPTION OF THE PRIOR ART Dies of the above-described character are produced as a rule by casting on a model of the desired article a polymer adapted to set according to a polyaddition or polycondensation reaction process and constituting a resilient material, i.e. a material resuming its initial shape when all stresses have been removed therefrom.

Under these conditions, it is clear that for each shoe model and more particularly for each toe end of each shoe model as many pairs of dies as there are shoe sizes must be prepared since the die designed for the toe end of a shoe for a left-hand foot cannot be used for mounting the toe end of a right shoe.

Therefore, it has been suggested to use more flexible materials capable of accommodating the shape and volume of the toe end of a shoe by pressure distortion, but also in this case difficulties were experienced because the amplitude of the compressive stress thus applied cannot be constant for all shoe sizes, thus precluding the possibility of producing a square toe having a portion lying in the plane of action of the folding plates.

SUMMARY OF THE INVENTION The present invention relates to a die for making the impression or die corresponding to the toe end of the shoe model while avoiding the inconveniences of the prior art devices and methods. This die comprises a frame element of semi-rigid but resilient materiaL'ineluding a base formed with at least one curved rib corresponding substantially in shape to the outer contour ofthe. toe end of the shoe contemplated, and, a filling of flexible and resilient material fitted in the cavity formed by the curved rib.

For instance, the frame element may consist of polyurethane having a' Shore A hardness in excess of 90, and the filling element may consist of polyurethane having Shore A hardness of less than 50.

With this arrangement, the rib of the element will check the distortion of the filling element and define with its free edge the plane of action of the folding plates.

According to another feature of this invention, the rib of the frame is not perpendicular to its base but forms therewith an angle imparting thereto the shape of a portion (segment) of the frustum of a cone of which the major base corresponds to the rib edge connected to the base. Furthermore the inclination of this rib is such that by'increasing the width of its top the device can be adapted to a number of shoe sizes or models before resorting to mechanical means for modifying its curvature, and on the other hand a retaining action is exerted on the skin. In fact when the last is sunk into the die it'causes the frame lips to diverge gradually whereby the skin lying between the frame rib and the filling element is retained braked" or locked, thus improving appreciably the mounting conditions. This arrangement further improves the control of the distortion to which .the filling element is subjected because the aforesaid inclination constitutes with respect to the element a counter-rake preventing the back-driving thereof towards the free edge of the rib.

According to another feature of the arrangement of this invention, a support of. rigid material is associated with said die frame and comprises means adapted resiliently to bear, directly or indirectly against the free ends of the rib so that the curvature of this rib can be changed as a function of the dimensions of the toe end of the shoe being mounted.

According to-a further feature of this invention, the

base carries, in addition to said curved rib, another rib of substantially rectangular contour. The truncated ends of one of the sides of this further rib are rigid with the free ends of the aforesaid curved rib.

I Advantageously, a filling material having a hardness selected as a function of the resistance to the radial thrust which is desired for the curved rib is disposed in the cavity formed between the rectangular rib and the curved rib.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view or the device according to this invention; I

FIG. 2 is a plan view from above of the same device;

and

FIG. 3 is a section taken along the line 33 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT:-

As shown in the drawing, the die intended for mounting the toe end of a shoe upper on a last comprises essentially two portions, i.e. a frame 2 of semi-rigid material and a filling material 3 of flexible, soft material. These materials are both obtained by casting on a model of the article to be produced a polymer adapted to set according to a polyaddition or polycondensation reaction process. The frame 2 comprises a base 4 supporting a rib 5 of generally curvilinear contour adapted, in the inoperative or unstressed condition, to assume the external contour or configuration of the toe end of the shoe during the mounting operation.

This rib 5 defines with the base 4 a cavity 6 in which the filling element 3 is disposed.

For example, the frame 2 consists of polyurethane having a Shore A hardness in excess of 90, and the tiller 3 consists of polyurethane but having a Shore A hardness of less than-50. a

As shown notably in FIG. 3, the curvilinear rib S is not perpendicular to its base 4 but forms therewith an angle such that the rib has a frustoconical profile,

whereby its free (exposed) edge corresponds to the minorbase of the cone, the rib end attached to said base 4 corresponding to the major base of the frustocone.

Under these conditions it is clear that when the filling element 3 is distorted as a consequence of the application of pressure from underneath to the toe end of a mounting last in the direction of the arrow 7, the taper of rib 5 acts thereon as a counter-rake preventing the filler from flowing in a direction opposite to that in which said pressure is exerted.

, Thus, the filling material is positively retained within the cavity 6 and assists in keeping the free face of this filling element 3 in the plane of the free edge of rib 5, this plane corresponding to the plane of action of the folding plates.

Moreover, this inclination of rib is such that it will retard or brake the skin'when the last is sunk into the die.

In the example illustrated in the drawing a rib 8 having a substantially rectangular contour is associated with the curvilinear rib 5 and has its ends, on the truncated side 8a, connected to the ends of the curvilinear rib 5, so as to constitute a single, continuous rib defining a second cavity 9 in which a flexible, soft material identical with the material constituting the filling element 3, can be packed, this material having if desired a different hardness to permit the adjustment to the desired value of the resistance of rib 5 to radial stresses.

From the foregoing, it is clear that the only requirement to be met is that the rib 5 have initially and in the inoperative position a contour corresponding substantially to that of the toe end of the shoe to be formed, since by deformation it is possible to impart thereto a contour corresponding exactlyto that of the toe end of shoes having different shapes and dimensions and therefore different sizes. Consequently, this arrangement affords a considerable reduction in the number of dies to be put at the shoe makers disposal.

In order further to improve the conditions of use of a same die suitable for mounting several shoe sizes, a rectangular rigid frame or strap 11 of rectangular shape is associated with said semi-rigid frame 2 and has its free ends provided with means adapted resiliently to engage the free ends of the curvilinear rib 5, notably through corresponding portions of said rectangular rib 8.

These resilient means consist for example of a spring 12 attached to one end of strap 11 and of a clamping screw 13 carried by the other end of said strap.

By turning the screw 13 in one or the other direction it is possible to modify at will the opening and therefore the curvature of rib 5 for approaching the contour of the shoe during the mounting thereof.

Of course, this invention should not be construed as being strictly limited by the specific form of embodiment described and illustrated herein by way of example, since various modifications as to relative proportions, materials and shapes may be brought thereto without departing from the basic principle of the inven tion as set forth in the appended claims.

We claim:

l. A die for forming a curved end of a shoe upper on a last, said die comprising a support body consisting essentially of a base and at least one rib upstanding for said base, said rib being curved essentially to the profile of said end and of said shoe upper, said body being composed of a semirigid but resilient material; and a filling element of a resilient material more flexible than that of said body received within and at least partly surrounded by said rib.

2. A die for forming an end of a shoe upper on a last, comprising a body of semirigid but resilient material including a base, and at least one rib curved substantially to the profile of the outer contour of said end of said shoe upper and upstanding from said base while defining a cavity, said rib being curved and having a downwardly divergent generally frustoconical configuration with a major base at said base of said body and a minor base at a free edge of said rib remote from said base of said body;-and a filling element of a resilient material more flexible than that of said body received in said cavity.

3. The die as defined in claim 2, further comprising a rigid frame receiving said body and formed with means at least indirectly acting upon said free end of said rib for displacing same to modify the rib curvature as a function of the dimensions of said end of said upper.

4. The die defined in claim 3 wherein said body is provided with a further rib of substantially rectangular contourupstanding from said base of said body and connected to opposite sides of the curved rib.

5. The die defined in claim 4 further comprising another filling of a material of selected hardness received between said ribs. 

1. A die for forming a curved end of a shoe upper on a last, said die comprising a support body consisting essentially of a base and at least one rib upstanding for said base, said rib being curved essentially to the profile of said end and of said shoe upper, said body being composed of a semirigid but resilient material; and a filling element of a resilient material more flexible than that of said body received within and at least partly surrounded by said rib.
 2. A die for forming an end of a shoe upper on a last, comprising a body of semirigid but resilient material including a base, and at least one rib curved substantially to the profile of the outer contour of said end of said shoe upper and upstanding from said base while defining a cavity, said rib being curved and having a downwardly divergent generally frustoconical configuration with a major base at said base of said body and a minor base at a free edge of said rib remote from said base of said body; and a filling element of a resilient material more flexible than that of said body received in said cavity.
 3. The die as defined in claim 2, further comprising a rigid frame receiving said body and formed with means at least indirectly acting upon said free end of said rib for displacing same to modify the rib curvature as a function of the dimensions of said end of said upper.
 4. The die defined in claim 3 wherein said body is provided with a further rib of substantially rectangular contour upstanding from said base of said body and connected to opposite sides of the curved rib.
 5. The die defined in claim 4 further comprising another filling of a material of selected hardness received between said ribs. 